Referring to FIG. 1, FIG. 1 is a side view of a structure of a common communications device in the prior art. The communications device includes a cabinet. At least one chassis may be placed in the cabinet, and each chassis includes a backplane. For engineering reliability, each backplane and chassis are integrated. Multiple boards may be inserted in each chassis, and the multiple boards are connected to a power supply and a fan by using the backplane in the chassis. The multiple boards may include a service board and a switch board. The multiple boards may be inserted in the chassis in manners such as horizontal insertion and vertical insertion, and are connected to the backplane. The power supply and the fan are also connected to the backplane. Wires for interactive signals between the multiple boards and switching signals between the multiple boards and the power supply and between the multiple boards and the fan is disposed on the backplane, and communication is completed by using the backplane.
With increasing high requirements on capabilities of communications devices, more pins are used to connect each board, a power supply, and a fan to a backplane, and cabling on the backplane also becomes more complex. Consequently, design of a backplane is more complex, and design costs are increased.